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What is prevention?

Cancer prevention is action taken to lower the chance of getting cancer. By preventing cancer, the number of new cases of cancer in a group or population is lowered. Hopefully, this will lower the number of deaths caused by cancer.

To prevent new cancers from starting, scientists look at risk factors and protective factors. Anything that increases your chance of developing cancer is called a cancer risk factor; anything that decreases your chance of developing cancer is called a cancer protective factor.

Some risk factors for cancer can be avoided, but many cannot. For example, both smoking and inheriting certain genes are risk factors for some types of cancer, but only smoking can be avoided. Regular exercise and a healthy diet may be protective factors for some types of cancer. Avoiding risk factors and increasing protective factors may lower your risk but it does not mean that you will not get cancer.

Different ways to prevent cancer are being studied, including:

Changing lifestyle or eating habits.

Avoiding things known to cause cancer.

Taking medicines to treat a precancerous condition or to keep cancer from starting.

General Information About Stomach Cancer

Stomach (gastric) cancer is a disease in which malignant (cancer) cells form in the stomach.

The stomach is a J-shaped organ in the upper abdomen. It is part of the digestive system, which processes nutrients (vitamins, minerals, carbohydrates, fats, proteins, and water) in foods that are eaten and helps pass waste material out of the body. Food moves from the throat to the stomach through a hollow, muscular tube called the esophagus. After leaving the stomach, partly-digested food passes into the small intestine and then into the large intestine.

The esophagus and stomach are part of the upper gastrointestinal (digestive) system.

See the following PDQ summaries for more information about stomach cancer:

Stomach (Gastric) Cancer Screening

Gastric Cancer Treatment

In the United States, the number of new cases of stomach cancer has stayed about the same since 2005.

Since 2005, the number of new cases of stomach cancer in the United States has stayed about the same. Men are twice as likely as women to be diagnosed with stomach cancer.

Stomach cancer is the fourth most common cancer in the world.

The number of deaths from stomach cancer has decreased over many years, especially in the United States. Black men are more than twice as likely as white men to die from stomach cancer.

Stomach Cancer Prevention

Avoiding cancer risk factors may help prevent certain cancers. Risk factors include smoking, being overweight, and not getting enough exercise. Increasing protective factors such as quitting smoking, eating a healthy diet, and exercising may also help prevent some cancers. Talk to your doctor or other health care professional about how you might lower your risk of cancer.

The following are risk factors for stomach cancer:

Certain medical conditions

Having any of the following medical conditions may increase the risk of stomach cancer:

Helicobacter pylori (H. pylori) infection of the stomach.

Intestinal metaplasia (a condition in which the cells that line the stomach are replaced by cells that normally line the intestines).

Chronic atrophic gastritis (thinning of the stomach lining caused by long-term inflammation of the stomach).

Genetic conditions may increase the risk of stomach cancer in people with any of the following:

A mother, father, sister, or brother who has had stomach cancer.

Type A blood.

Li-Fraumeni syndrome.

Familial adenomatous polyposis (FAP).

Hereditary nonpolyposis colon cancer (HNPCC; Lynch syndrome).

Diet

The risk of stomach cancer may be increased in people who:

Eat a diet low in fruits and vegetables.

Eat a diet high in salted or smoked foods.

Eat foods that have not been prepared or stored the way they should be.

Environmental causes

Environmental factors that may increase the risk of stomach cancer include:

Being exposed to radiation.

Working in the rubber or coal industry.

The risk of stomach cancer is increased in people who come from countries where stomach cancer is common.

The following are protective factors that may decrease the risk of stomach cancer:

Stopping smoking

Studies show that smoking is linked with an increased risk of stomach cancer. Stopping smoking or never smoking decreases the risk of stomach cancer. Smokers who stop smoking lower their risk of having stomach cancer over time.

Treating Helicobacter pylori infection

Studies show that chronic infection with Helicobacter pylori (H. pylori) bacteria is linked to an increased risk of stomach cancer. When H. pylori bacteria infects the stomach, the stomach may become inflamed and cause changes in the cells that line the stomach. Over time, these cells become abnormal and may become cancer.

Some studies show that treating H. pylori infection with antibiotics lowers the risk of stomach cancer. More studies are needed to find out whether treating H. pylori infection with antibiotics lowers the number of deaths from stomach cancer or keeps changes in the stomach lining, that can lead to cancer, from getting worse.

It is not known if the following factors lower the risk of stomach cancer or have no effect on the risk of stomach cancer:

Diet

Not eating enough fresh fruits and vegetables is linked to an increased risk of stomach cancer. Some studies show that eating fruits and vegetables that are high in vitamin C and beta carotene may lower the risk of stomach cancer. Studies also show that whole-grain cereals, carotenoids, green tea, and substances found in garlic may lower the risk of stomach cancer.

Studies show that eating a diet with a lot of salt may increase the risk of stomach cancer. Many people in the United States now eat less salt to lower their risk of high blood pressure. This may be why rates of stomach cancer have decreased in the U.S.

Dietary supplements

It is not known if taking certain vitamins, minerals, and other dietary supplements helps lower the risk of stomach cancer. In China, a study of beta carotene, vitamin E, and selenium supplements in the diet showed a lower number of deaths from stomach cancer. The study may have included people who did not have these nutrients in their usual diets. It is not known if increased dietary supplements would have the same effect in people who already eat a healthy diet.

Other studies have not shown that taking dietary supplements such as beta carotene, vitamin C, vitamin E, or selenium lowers the risk of stomach cancer.

Cancer prevention clinical trials are used to study ways to prevent cancer.

Cancer prevention clinical trials are used to study ways to lower the risk of certain types of cancer. Some cancer prevention trials are done with healthy people who have not had cancer but who have an increased risk for cancer. Other prevention trials are done with people who have had cancer and are trying to prevent another cancer of the same type or to lower their chance of developing a new type of cancer. Other trials are done with healthy volunteers who are not known to have any risk factors for cancer.

The purpose of some cancer prevention clinical trials is to find out whether actions people take can prevent cancer. These may include eating fruits and vegetables, exercising, quitting smoking, or taking certain medicines, vitamins, minerals, or food supplements.

New ways to prevent stomach cancer are being studied in clinical trials.

Clinical trials are taking place in many parts of the country. Information about clinical trials can be found in the Clinical Trials section of the NCI website. Check NCI's list of cancer clinical trials for stomach cancer prevention that are now accepting patients.

About This PDQ Summary

About PDQ

Physician Data Query (PDQ) is the National Cancer Institute's (NCI's) comprehensive cancer information database. The PDQ database contains summaries of the latest published information on cancer prevention, detection, genetics, treatment, supportive care, and complementary and alternative medicine. Most summaries come in two versions. The health professional versions have detailed information written in technical language. The patient versions are written in easy-to-understand, nontechnical language. Both versions have cancer information that is accurate and up to date and most versions are also available in Spanish.

PDQ is a service of the NCI. The NCI is part of the National Institutes of Health (NIH). NIH is the federal government's center of biomedical research. The PDQ summaries are based on an independent review of the medical literature. They are not policy statements of the NCI or the NIH.

Purpose of This Summary

This PDQ cancer information summary has current information about stomach (gastric) cancer prevention. It is meant to inform and help patients, families, and caregivers. It does not give formal guidelines or recommendations for making decisions about health care.

Reviewers and Updates

Editorial Boards write the PDQ cancer information summaries and keep them up to date. These Boards are made up of experts in cancer treatment and other specialties related to cancer. The summaries are reviewed regularly and changes are made when there is new information. The date on each summary ("Date Last Modified") is the date of the most recent change.

The information in this patient summary was taken from the health professional version, which is reviewed regularly and updated as needed, by the PDQ Screening and Prevention Editorial Board.

Clinical Trial Information

A clinical trial is a study to answer a scientific question, such as whether one treatment is better than another. Trials are based on past studies and what has been learned in the laboratory. Each trial answers certain scientific questions in order to find new and better ways to help cancer patients. During treatment clinical trials, information is collected about the effects of a new treatment and how well it works. If a clinical trial shows that a new treatment is better than one currently being used, the new treatment may become "standard." Patients may want to think about taking part in a clinical trial. Some clinical trials are open only to patients who have not started treatment.

Clinical trials are listed in PDQ and can be found online at NCI's website. Many cancer doctors who take part in clinical trials are also listed in PDQ. For more information, call the Cancer Information Service 1-800-4-CANCER (1-800-422-6237).

Permission to Use This Summary

PDQ is a registered trademark. The content of PDQ documents can be used freely as text. It cannot be identified as an NCI PDQ cancer information summary unless the whole summary is shown and it is updated regularly. However, a user would be allowed to write a sentence such as "NCI's PDQ cancer information summary about breast cancer prevention states the risks in the following way: [include excerpt from the summary]."

Images in this summary are used with permission of the author(s), artist, and/or publisher for use in the PDQ summaries only. If you want to use an image from a PDQ summary and you are not using the whole summary, you must get permission from the owner. It cannot be given by the National Cancer Institute. Information about using the images in this summary, along with many other images related to cancer can be found in Visuals Online. Visuals Online is a collection of more than 2,000 scientific images.

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The information in these summaries should not be used to make decisions about insurance reimbursement. More information on insurance coverage is available on Cancer.gov on the Managing Cancer Care page.

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Last Revised: 2015-12-01

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